It is proposed in Japanese Patent Application Laid-open No. 11-12546 (corresponding U.S. Pat. No. 6,235,862) that a silicone-based adhesive sheet obtained by curing a hydrosilylation-curable silicone composition sandwiched between two protective films can be used for bonding a semiconductor chip and a chip attachment component. However, such sheets have had problems in that when irregularities of 10 μm or greater (gaps) occur in the surface of the semiconductor chip and/or the chip attachment component, the ability to fill the gaps decreases and the two cannot be sufficiently bonded.
A clay-like sheet adhesive having a thickness of 0.1 to 5 millimeters (mm) and comprising an organopolysiloxane, a filler, and a silicone composition containing an adhesion promoter is proposed in Japanese Patent Application Laid-open No. 10-17828 (corresponding U.S. Pat. No.5,942,565). However, bonding a base and another base using such a sheet adhesive has had problems in that the thickness of the bonded layer is nonuniform. Particularly when a semiconductor chip is bonded to a chip attachment component by means of such a sheet adhesive, problems have arisen in that the thickness of the bonded layer becomes nonuniform, causing inconveniences in subsequent wire bonding processes.
Therefore, an object of this invention is to provide a silicone-based adhesive sheet whereby a smooth base and a base having irregularities in the surface can be bonded in a satisfactory manner, and wherein the thickness of the bonded layer can be made nearly uniform; to provide a method of bonding a semiconductor chip to a chip attachment component wherein the semiconductor chip and the chip attachment component can be satisfactorily bonded together even if at least one of the two has irregularities in the surface; and to provide a semiconductor device with superior reliability, wherein the semiconductor chip and the chip attachment component can be satisfactorily bonded together even if at least one of the two has irregularities in the surface.